138 Rockwell Automation Publication 825-UM004D-EN-P - November 2012
Chapter 10 Modbus RTU Communications
Table 70 - 06h Preset Single Register Command
The relay responses to errors in the query are shown in Table 71.
Table 71 - Responses to 06h Preset Single Register Query Errors
10h Preset Multiple
Registers Command
This function code works much like code 06h, except that it allows you to write
multiple registers at once, up to 100 per operation. If you are accustomed to 4X
references with the function code, for six-digit addressing, simply add 400001 to
the standard database addresses.
Table 72 - 10h Preset Multiple Registers Command
Bytes Field
Requests from the master must have the following format:
1 byte Slave Address
1 byte Function Code (06h)
2 bytes Register Address
2 bytes Data
2 bytes CRC-16
Error Error Code Returned Communication Counter
Increments
Illegal register address Illegal Data Address (02h) Invalid Address
Illegal Write
Illegal register value Illegal Data Value (03h) Illegal Write
Format error Illegal Data Value (03h) Bad Packet Format
Bytes Field
Requests from the master must have the following format:
1 byte Slave Address
1 byte Function Code (10h)
2 bytes Starting Address
2 bytes Number of Registers to Write
1 byte Bytes of Data (n)
n bytes Data
2 bytes CRC-16
A successful response from the slave will have the following format:
1 byte Slave Address
1 byte Function Code (10h)
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